From: Kathryn Aegis (aegis@igc.apc.org)
Date: Tue Nov 17 1998 - 21:30:55 MST
This is one of two postings that should have been posted weeks ago......
In mid-October, the American Society for Reproductive Medicine held its
annual meeting, and unveiled several developments, one set of which may have
implications for cryonics.
*** FREEZING THE HUMAN EGG***
Several groups of researchers announced that they had successfully frozen
and thawed the human egg. The human egg has represented a major challenge,
because it is the largest single cell in the human body, contains more water
and subject to damaze from ice crystals.
Several methods were used in these experiments. In one conducted by James
Stachecki, et al, at the Institute for Reproductive Medicine and Science of
Saint Barnabas, West Orange, New Jersey, a solution was prepared that
replaced sodium with potassium and choline, with the end of reducing
positive ionic charges. They then froze mouse eggs in nitrogen to test the
procedure, and found that they could produce mouse embryos upon thawing.
Testing on human eggs, 10 out of 10 thawed successfully and 9 were
successfully fertilized, 7 developed into human embryos.
Researchers from Argentina claimed to have created 13 live embryos from 83
frozen eggs and transferred them into the wombs of 3 women. Could not find
many details on this one, there seems to be some question as to the validity
of the claim. They were the only group to implant in human women.
Kwang Yul Cha from Pochon CHA University, Seoul, Korea, has developed a
technique utilizing the antifreeze ethylene glycol, which turns the fluid in
the egg to a glassy substance instead of ice crystals. He experienced a 2/3
success rate in thawing and a 90 percent success rate in cell division.
Unfortunately, the health of the cells were questionable and none were
brought to the embryo stage.
Another technique being studied by researchers in England, France and Israel
involves slicing out ovarian tissue that contains immature eggs, freezing
the eggs in liquid nitrogen, thawing the tissue, and then implanting it into
the thigh muscle of a mouse. (And these people think *we're* the wierd
ones?) A team led by Joseph Itsokovitz-Eldor in Israel's Ramban Medical
Center found that many of these grafts survived, but none of the eggs
matured to the point of being able to be fertilized. The hope is of someday
being able to restore a woman's menstrual cycle through this technique.
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